* WGs marked with an * asterisk has had at least one new draft made available during the last 5 days

Codec Status Pages

Internet Wideband Audio Codec (Concluded WG)
Art Area: Barry Leiba, Murray Kucherawy | 2010-Jan-26 — 2018-Sep-20 

2017-03-30 charter

Internet Wideband Audio Codec (codec)


 Current Status: Active

     Mo Zanaty <mzanaty@cisco.com>
     Tim Terriberry <tterriberry@mozilla.com>

 Applications and Real-Time Area Directors:
     Ben Campbell <ben@nostrum.com>
     Alexey Melnikov <aamelnikov@fastmail.fm>
     Adam Roach <adam@nostrum.com>

 Applications and Real-Time Area Advisor:
     Ben Campbell <ben@nostrum.com>

 Tech Advisor:
     Stephan Wenger <stewe@stewe.org>

 Mailing Lists:
     General Discussion: codec@ietf.org
     To Subscribe:       https://www.ietf.org/mailman/listinfo/codec
     Archive:            https://mailarchive.ietf.org/arch/browse/codec/

Description of Working Group:

    Problem Statement

    According to reports from developers of Internet audio applications and
    operators of Internet audio services, there are no standardized,
    high-quality audio codecs that meet all of the following three

    1. Are optimized for use in interactive Internet applications.

    2. Are published by a recognized standards development organization
    (SDO) and therefore subject to clear change control.

    3. Can be widely implemented and easily distributed among application
    developers, service operators, and end users.

    There exist codecs that provide high quality encoding of audio
    information, but that are not optimized for the actual conditions of the
    Internet; according to reports, this mismatch between design and
    deployment has hindered adoption of such codecs in interactive Internet

    There exist codecs that can be widely implemented and easily
    distributed, but that are not standardized through any SDO; according to
    reports, this lack of standardization and clear change control has
    hindered adoption of such codecs in interactive Internet applications.

    There exist codecs that are standardized, but that cannot be widely
    implemented and easily distributed; according to reports, the presence
    of various usage restrictions (e.g., in the form of requirements to pay
    royalty fees, obtain a license, enter into a business agreement, or meet
    other special conditions imposed by a patent holder) has hindered
    adoptions of such codecs in interactive Internet applications.

    According to application developers and service operators, an audio
     codec that meets all three of these would: (1) enable protocol
     designers to more easily specify a mandatory-to-implement codec in
     their protocols and thus improve interoperability; (2) enable
     developers to more easily easily build innovative, interactive
     applications for the Internet; (3) enable service operators to more
     easily deploy affordable, high-quality audio services on the Internet;
     and (4) enable end users of Internet applications and services to enjoy
     an improved user experience.


    The goal of this working group is to ensure the existence of a single
    high-quality audio codec that is optimized for use over the Internet and
    that can be widely implemented and easily distributed among application
    developers, service operators, and end users.  At present it appears
    that ensuring the existence of such a codec will require a development
    effort within the working group, however if a candidate codec is
    presented that achieves the goal then the working group should seriously
    consider stopping its development work.

    The core technical considerations for such a codec include, but
    are not necessarily limited to, the following:

    1. Designing for use in interactive applications (examples include, but
    are not limited to, point-to-point voice calls, multi-party voice
    conferencing, telepresence, teleoperation, in-game voice chat, and live
    music performance)

    2. Addressing the real transport conditions of the Internet as
    identified and prioritized by the working group

    3. Ensuring interoperability and clean integration with the Real-time
    Transport Protocol (RTP), including secure transport via SRTP

    4. Ensuring interoperability with Internet signaling technologies such
    as Session Initiation Protocol (SIP), Session Description Protocol
    (SDP), and Extensible Messaging and Presence Protocol (XMPP); however,
    the result should not depend on the details of any particular signaling

    Optimizing for very low bit rates (typically below 2.4 kbps) and for
    non-interactive audio is out of scope because such work might
    necessitate specialized optimizations.

    Although a codec produced by this working group or another standards
    organization might be used as a mandatory-to-implement technology by
    designers of particular Internet protocols, it is explicitly not a goal
    of the working group to produce or select a codec that will be mandated
    for use across the entire IETF or Internet community nor would their be
    any expectation that this would be the only mandatory-to-implement

    Based on the working group's analysis of the design space, the working
    group might determine that it needs to produce more than one codec, or a
    codec with multiple modes; however, it is not the goal of working group
    to produce more than one codec, and to reduce confusion in the
    marketplace the working group shall endeavor to produce as few codecs as

    In completing its work, the working group should collaborate with other
    IETF working groups to complete particular tasks.  These might include,
    but would not be limited to, the following:

    - Within the AVT WG, define the codec's payload format for use with the
      Real-time Transport Protocol (RTP).

    - Collaborate with working groups in the Transport Area to identify
      important aspects of packet transmission over the Internet.

    - Collaborate with working groups in the Transport Area to understand
      the degree of rate adaptation desirable, and to reflect that
      understanding in the design of a codec that can adjust its
      transmission in a way that minimizes disruption to the audio.

    - Collaborate with working groups in the RAI Area to ensure that
      information about and negotiation of the codec can be easily
      represented at the signaling layer.

    In accordance with the liaison agreement in place, the working group
    will continue to coordinate with the ITU-T (Study group 16), with the
    intent of submitting the completed codec RFC for co-publication by the
    ITU-T if the ITU-T finds that appropriate. The working group will
    communicate a detailed description of the requirements and goals to
    other SDOs including the ITU-T, 3GPP, and MPEG to help determine if
    existing codecs meet the requirements and goals. Information about
    codecs being standardized will be available to other SDOs in the form of
    internet drafts and the working group welcomes technical feedback from
    other SDOs and experts from other organizations.

    Suggested Codec Standardization Guidelines and Requirements for
    achieving the foregoing objectives are provisionally outlined in
    draft-valin-codec-guidelines and draft-valin-codec-requirements
    respectively; these documents will form the starting point for working
    toward consensus and, if accepted as work items of the working group,
    will be refined by the working group in accordance with the usual IETF

    A codec that can be widely implemented and easily distributed among
    application developers, service operators, and end users is preferred.
    Many existing codecs that might fulfill some or most of the technical
    attributes listed above are encumbered in various ways.  For example,
    patent holders might require that those wishing to implement the codec
    in software, deploy the codec in a service, or distribute the codec in
    software or hardware need to request a license, enter into a business
    agreement, pay licensing fees or royalties, or attempt to adhere to
    other special conditions or restrictions.

    Because such encumbrances have made it difficult to widely implement and
    easily distribute high-quality audio codecs across the entire Internet
    community, the working group prefers unencumbered technologies in a way
    that is consistent with BCP 78 and BCP 79.  In particular, the working
    group shall heed the preference stated in BCP 79: "In general, IETF
    working groups prefer technologies with no known IPR claims or, for
    technologies with claims against them, an offer of royalty-free
    licensing."  Although this preference cannot guarantee that the working
    group will produce an unencumbered codec, the working group shall follow
    BCP 79, and adhere to the spirit of BCP 79. The working group cannot
    explicitly rule out the possibility of adopting encumbered technologies;
    however, the working group will try to avoid encumbered technologies
    that require royalties or other encumbrances that would prevent such
    technologies from being easy to redistribute and use.


    1. A set of Codec Standardization Guidelines that define the work
    processes of the working group. This document shall be Informational.

    2. A set of technical Requirements. This document shall be

    3. Specification of a codec that meets the agreed-upon requirements, in
    the form of an Internet-Draft that defines the codec algorithm along
    with source code for a reference implementation.  The text description
    of the codec shall indicate which components of the encoder and decoder
    are mandatory, recommended, and optional.  It is envisioned that this
    document shall be a Proposed Standard document.

Goals and Milestones:
  Done     - WGLC on Codec Standardization Guidelines
  Done     - WGLC on Requirements, liaise to other SDOs
  Done     - Requirements to IESG (Informational)
  Done     - Liaise requirements RFC to other SDOs
  Done     - WGLC on codec specification, liaise to other SDOs
  Done     - Codec Standardization Guidelines to IESG (Informational)
  Done     - WGLC #2 on Codec specification
  Done     - Submit codec specification to IESG (Standards Track)
  Done     - Container format for OPUS codec to IESG as PS
  Nov 2016 - Submit Ambisonics channel mapping to IESG (Standards Track)
  Feb 2017 - Error and bugfix update(s) to RFC 6716

All charter page changes, including changes to draft-list, rfc-list and milestones:

Generated from PyHt script /wg/codec/charters.pyht Latest update: 24 Oct 2012 16:51 GMT -